The power within

Imagine detecting mastitis before you even collect a drop of milk. It’s closer to reality than you may think.

Researchers are studying various technologies and how they can be used to detect sick cows. One such technology uses temperature-sensing rumen boluses. It’s currently being looked at as an early-warning system for mastitis. You’ll still need to collect milk samples to make a diagnosis, but it can give you a leg up on which cows to sample. Here is a look at what researchers have learned so far about this technology.

A milk-free system

Hands-free technology allows you to talk on your mobile phone while still keeping both hands on the wheel. A mastitis-detection system under study at the University of Kentucky applies a similar principle: It’s designed to keep you connected with the cows, but free of collecting milk samples. The system uses a rumen bolus, a radio-frequency identification (RFID) transponder and a panel reader to monitor core body temperature. During a study at the university farm, cows fitted with the transponders and boluses walked past a panel reader placed in the parlor entrance. The system recorded the cows’ core body temperature twice a day in conjunction with milking time. The researchers collected a milk sample from each cow every 14 days for somatic cell count analysis. Milkers also recorded clinical mastitis cases.

Overall, the system did a pretty good job of pinpointing cows with mastitis, but there is room for improvement.

“We were able to detect many, but not all, of the mastitis events,” says Jeffrey Bewley, assistant professor of animal and food sciences at the University of Kentucky.

Making the system more sensitive and specific is an ongoing goal of the research and something that could certainly improve the percentage of mastitis cases detected.

One area that could be improved is how often the boluses measure body temperature. In this study, it was twice a day, which presented a problem if a cow took a drink of water right before her trip past the panel reader.

“One of the biggest limitations is that every time a cow drinks water, there’s going to be a drop in temperature,” Bewley explains. “That temperature isn’t really reflective of the cow’s core body temperature.”

In fact, it can take at least an hour for her temperature to adjust itself.

Since this study took place, the company that makes the boluses (DVM Systems, LLC, of Boulder, Colo.) has developed boluses that measure temperature much more frequently (every hour, even every two minutes), says Amanda Sterrett, graduate research assistant at the University of Kentucky. More frequent monitoring could help them weed out the values influenced by water intake.

Minimizing “false positives” is also a work in progress for researchers studying these technologies.

“One of the most important things that we have to recognize with any kind of alert system is that balance between sensitivity and specificity,” Bewley says. “Basically, we want to be able to detect whatever we’re looking for (mastitis), but we also have to make sure the alerts don’t have a lot of false positives.”

For example, say you have 20 cows come up on a daily alert list, but only two of them truly have mastitis. You just spent an unnecessary amount of time working with those other 18 cows that didn’t need your attention.

“The false positive rate is something that we really need to look at,” Bewley says. “There’s a balance between catching it and getting false positives, and the two are always fighting against each other.”

What else is out there?

Technology that uses rumen boluses to detect sick cows is just one of several tools that could serve as an alternative or supplement to common cow-side mastitis tests.

Here’s a brief look at some mastitis-detection technologies that are already available or in the pipeline.

• Electrical conductivity measures the concentration of cations and anions in milk, which undergo changes when a cow has mastitis. This technology has been around for several years.

• In-line sensors in the milking system that essentially automate SCC sampling have been commercialized in Europe and New Zealand.

• Biosensors detect the milk enzyme L-Lactate dehydrogenase (LDH), which is released during an immune response and serves an early indication of mastitis.

• Behavior-monitoring systems assess how much time a cow spends lying down. A change in resting behavior may be an indication of impending illness, including mastitis.

Application of any mastitis-detection technology needs to be well thought out, Bewley cautions. See what’s available to you and ask some tough questions about the system’s detection capabilities before investing in it.